This application claims the priority of German application Nos. 197 09 909.2 and 197 22 099.1, filed on Mar. 11, 1997 and May 27, 1997, respectively, the disclosures of which are expressly incorporated by reference herein.
This invention concerns a heat transfer device for a motor vehicle with a rib/tube fin/tube block arranged between two collection containers. The tube ends of the fin/tube block are all widened in areas of the collection containers and are brought together into a tube end packet. Both collection containers are set flush to the respective tube end packet and brazed hermetically to the same.
A heat transfer device of this type is described in unpublished German application DE 19,543,986.4. In heat transfer devices of this kind, a fin/tube block including flat tubes and corrugated ribs is provided. The tube ends of the flat tubes are widened to produce square sections so that the neighboring tube ends lie flat against each other in a row with the wall sections representing their wide sides. The wall sections representing the narrow sides of the widened tube ends are arranged at each side in a mutual straight line. The tube ends form a compact and closely-lying tube end packet at each of the opposing sides of the flat tubes. A collection container is arranged at each tube end packet and grips onto the narrow area formed by the narrow sides of the tube ends from outside. The container lies flush against the tube ends as a result of the narrow area formed by the narrow sides. The collection containers grip directly over the widened tube ends in the longitudinal direction and produce a hermetic connection due to the flush position in the longitudinal direction. Consequently, the heat transfer device requires no additional bottom in the area of the collection containers. Both the collection containers and the fin/tube block are made out of metal plates that can be connected to each other by mutual brazing.
A primary object of the invention is to provide a heat transfer device of the kind described above which facilitates an improved guidance of the circulation medium through the collection containers and the flat tubes of the fin/tube block.
This primary object is attained by providing a particular construction including at least one partition wall in at least one of the collection containers which has an outer contour corresponding to that of the inner contour of the wall of the collection container so that the outer contour can be brazed hermetically around this inner contour, and in which the tube ends of the tube end packet have two neighboring flush interlocking wall sections for insertion into a gap defined by a holding leg provided on the partition wall. By providing at least one partition wall in one of the two collection containers, it is possible to deviate the circulation medium within the fin/tube block so that the medium flows in a path taking the shape of a "U". The connections for the input and output of the circulation medium can be provided, if necessary, on one of the collection containers. The collection containers have collection or distribution functions, depending upon their connections to the corresponding circulation medium flow. Coolant, water, or air, in particular, can be utilized as the circulation medium. The heat transfer device can be any of a coolant/air, water/air, or air/air radiator. The air/air radiator is a load air radiator. In heat transfer devices with tube bottoms, it is already known to have partition walls. According to the invention, at least one partition wall can be provided in collection containers where an additional tube bottom is not provided. The containers are positioned directly on the widened tube ends of the fin/tube block. The partition wall is structured in such a way that it can be integrated during premounting of the complete heat transfer. The partition wall can then be connected hermetically to the collection container and the corresponding tube ends together with the remaining parts of the heat transfer device in a brazing oven by a mutual brazing process. Because of the provision of the holding leg, the partition wall can be installed in a simple manner before mounting the collection container onto the corresponding wall sections of the corresponding tube ends.
According to one feature of preferred embodiments of the invention, the holding leg has at least one one-piece bridge-like latch which protrudes from the partition wall and forms a receiving slit. The receiving slit is structured in such a manner that the partition wall can be set in different positions along the wall sections before the brazing step and, in any event, can even be pushed along the wall sections of the tube ends for adjustment.
According to another feature of preferred embodiments of the invention, the holding leg is provided with centering protrusions for inserting into the wall sections of the tube ends. Insertion of the partition wall into the wall sections of the corresponding tube ends is simplified by these centering protrusions. The partition wall is held force-fittingly on the corresponding tube ends by the holding leg.
According to a further feature of preferred embodiments of the invention, the partition wall has a distance to the holding leg for at least one fixing nose, which reaches into a corresponding gap in the wall of the collection container in the assembled condition of the partition wall. In this way, an additional form-fitting fixing of the partition wall onto the collection container is obtained, so that an extraordinarily stable partition of the collection container is achieved. It is therefore possible to allow high pressure fluid circulation within the heat transfer device before the partition wall is held form-fittingly to the wall sections of the corresponding tube ends. The fixing nose, similar to the latch, is also made as a single piece with the holding leg, so that the partition wall can be structured as a very simple stamped plate piece.
According to a further feature of preferred embodiments of the invention, the fixing nose is provided with at least one deformable protruding corner, which reaches through the gap in the wall of the collection container in the mounted or assembled condition of the partition wall, and which is deformed in such a way that it grips form-fittingly onto the back of an edge of the gap at the outer side of the collection container. It is possible in this way to improve the form-fit between the partition wall and the collection container before brazing the complete heat transfer unit. The protruding corners are bent in a simple manner so that a firm grip on the outer side of the collection container is achieved. The protruding corners are advantageously arranged on the opposite sides of the fixing nose and lie opposite each other. The protruding corners are deformed in the same (clockwise) direction. In this way, a secure grip between the partition wall and the collection container results before soldering. The partition wall, in the premounted condition of the heat transfer unit, i.e., before carrying out the soldering process, is already securely and clearly positioned as a result.
According to yet a further feature of preferred embodiments of the invention, the collection container has at least one positioning rib in the area of the partition wall that extends along a plane parallel to the partition wall, onto which the partition wall leans flat in the assembled position. The stable positioning of the partition wall is further improved by this form-fitting arrangement.
According to yet another feature of preferred embodiments of the invention, two parallel, evenly distanced positioning ribs are provided at the collection container, and the partition wall is provided with support edges that correspond in size to the distance of the positioning ribs so that the partition wall is held axially secure between the positioning ribs with respect to a longitudinal axis of the collection container. In this way, the positioning ribs form oblique guides and arrangements for the partition wall, so that a defined installation of the partition wall within the collection container is obtained. The partition wall is preferably premounted before it is installed at the corresponding tube end packet. With the additional installation of the collection container, the partition wall is inserted at the corresponding wall sections of two neighboring tube ends by use of its holding leg.